Commutator-brush holder



(No Madel.)

J J WOOD GOMMUTATOR BRUSH HOLDER.

No. I507,344. Patentd Oct. 24, 1893.

INVENTOR:

` By his' Atomeys,

UNITED STATES PATENT OFFICE.

JAMES J. WOOD, OF FORT WAYNE, INDIANA.

COMMUTATOR-BRUSH HOLDER.

SPECIFIGATION forming part of Letters Patent No. 507,344, dated October24, 1893.

Application filed .Tune 27, 1893. Serial No. 478,964. (No model.)

'Z'o aZZ whom it may concern:

Be it known that I, JAMES J. WOOD, a citizen of the United States,residing at Fort Wayne, in the county of Allen and State of Indiana,have invented certain new and useful Improvements in Commutator- BrushHolders, of which the following is a specification.

This invention introduces certain improvements in the construction ofholders for the copper brushes of the commutators or collectors ofdynamo electric machines.

The accompanying drawings show the preferred construction.

Figure 1 is afront elevation, and Fig. 2 an end elevation of the brushholder and brushes as applied to the supporting stud. Fig. 3 is asection of the brush holder removed from the stud, the section being cuton the lines 3-3 in Fig. 1. Fig. 4 is a section on the line 4-4 in Fig.2. Fig. 5 shows the side and end of the socket-piece, and Fig. 6 showsthe boss or set-piece in plan and side view. Fig. 7 shows the coppersleeve.

Let a. in Figs. 1 and 4 designate a portion of the cylindrical surfaceof the commutator, and b in Figs. 1, 2 and 4 designate the stud uponwhich the commutator brush holder is supported, this stud being itselfsupported upon the dynamo in any suitable way.

LetA designate the brush holder as a whole, and B the brush which asusual is made of laminated copper. The brush holder A is self-contained,and separable from the stud b without impairing its adjustment.

The brush holder consists of a socket-piece C, shown separately in Fig.5, a boss or setpiece D shown separately in Fig. 6, a gib E carrying astiffening plate or spring e, a conducting sleeve F preferably of coppershown separaiely in Fig. 7, a spring S, and the requisite adj ustingscrews.

The socket-piece Cis formed with the usual socket c for receiving thebrush, having a seat d and bridge f, the latter havinga threaded holefor receiving the screw g which clamps the gib E against the brush andthereby confines the latter against the seat cl. The gib is held fromdisplacement by two pins h h (Fig. 2) passing freelythrough holes in thebridge. The socket-piece is connected to the supporting stud in pivotalmanner lby being formed with two perforated ears the openings in whichslip over the stud, the sleeve F however intervening.

The boss or set-piece D consists of a tubular boss or hub adapted toslip over the stud, with the intervention however of the sleeve F, andformed with an arm D' having a threaded hole in which works the adjusting screw G. This arm is preferably slitted to give it elasticity,and a screw j is provided for drawing its opposite parts together toclamp the adj usting screw with any desired amount of friction. The bossD is also provided with a socket k for receiving one end of the springS, which is firmly fastened therein by means of a screw. The spring is aflat or leaf spring, and is bent around the hub portion of the boss, itsopposite end being fastened or clamped by a screw Z to the socket-pieceO. This spring acts in such direction as to tend to press the tip of thebrush away from the commutator, the brush being forced toward thecommutator by the adj ustment of the screw G, the tip of which bearsupon the socket-piece O underneath the seat d in the manner shown, sothat by screwing the screw forward it presses the brush toward thecommutator in opposition to the tension of the spring. The boss D isheld in place by means of a set-screw H entering through athreaded holein the boss, and the end of which enters a recess in the'stud b, thisreoess being preferably constructed as a longitudinal keyway, in orderthat the brush holder may be set in place at different points lengthwiseof the stud, so as to bring the brush to any desired adj ustment againstthe face of the commutator. By this set-screw the boss D is firmlyunited to the stud so as to resist the tension exerted against it byeither the spring S 01- the screw G. The boss D fits between theperforated ears i i of the socket-piece, as shown in Fig. 3, so thatwhen the boss is set in position on the stud it holds the socketpieceagainst displacement longitudinally of the stud.

The metal sleeve F is introduced between the socket-piece and boss onthe one hand and the stud on the other, and serves two purposes: first,it serves toimprove the electrical connection between the stud and theother parts of the brush-holder, since it afiords a IOO broad surfacethe contact of which with the stud is not materially impaired by theeccentric displacement of the boss D by the tightening of the screw H;and the second, it serves as a means for connecting together thesocketpiece O and boss D in such manner as to pre- Vent theirperforations being forced out of alignment by the tension of the springS. It thus renders the brush holder self-contained, in order that byloosening the set--screw I-I the entire brush holder may be slipped offfrom the stud b without impairing the adjustment of the brush relativelyto the commutator, this adj ustment being preserved while the brush isremoved, so that upon replacing the brush it does not requirere-adjustment.

Heretofore in brush holders wherein the brush is pressed away from thecommutator by a spring and adj usted toward the commutator by anadjusting screw, this screw has been carried by the socket-piece and hasreacted against an arm projecting from the stud Z), and which arm formedpart of the stud and no proper part of the brush holder.

My present invention reverses the adj usting screw, causing it to workthrough the arm and bear against the socket-piece and constructs the armnot as an integral part of the stud, but as part of a boss or set-piecewhich is adjustably clamped upon the stud. This construction simplifiesthe manufacture, and has the advantage of enabling the brush holder tobe set to different positions along the stud, and to be removed withoutimpairing the adjustlnent.

Heretofore in brush holders either a laminated copper spring has servedas the sole support of the brush socket, the socket-piece being nototherwise connected with the supporting stud or frame, or else when thesocket-piece has been pivotally mounted on the stud, a steel spring hasbeen introduced to exert a pressure upon the brush socket, beingfastened to or reacting upon the stud. In the former construction thecurrent is carried solely by the laminated copper spring, whichconsequently has to be fully as massive as the commutator brush. In thelatter construction the current is designed to be carried between thestud and brush through the socketpiece, but this would not be applicablefor heavy currents, because any imperfections of electrical contactbetween the two, would cause a portion of the current to be divertedthrough the spring, so that the spring would be heated and its tensionimpaired. To obviate this disadvantage, I construct the brush holderwith a double or composite spring S, the same consisting of a steelspring to afford the necessary elasticity, and a laminated copper springfor conducting any current that might otherwise tend to pass between theboss and socket-piece through the steel spring. The steel spring islettered 8, and the laminated copper Springs lettered s', the steelspring being preferably inside and the copper lamina extended around itsexterior so as to bind ose against it.

The sleeve F is a simple piece of copper tube with a hole m through itto admit the end of the set-screw H. This sleeve may be made either aloose or driving fit with the boss D, but must be a free or working fitwith the ears z' z' of the socket-piece.

A modification retaining part of my invention would consist in omittingthe sleeve F, and bringing the boss and socket-piece ears into directcontact, but this would be an inferior construction.

I claim as my invention the following-defined novel features,substantially as hereinbefore specified,name1y:

1. In combination with a supporting stud, a commutator brush-holderconsisting of a socket-piece having a pivotal bearing on said stud, anda boss having a screw for fixing it to said stud, and an adj ustingscrew working in said boss and acting against said socketpiece to rockit on said stud and adjust the brush against the commutator.

2. In combination with a supporting stud, a commutator brush-holderconsisting of a socket-piece having opposite perforated cars engagingthe stud and forming a pivotal bearing thereon for the socket-piece, aboss detachably fixed on said stud between said ears whereby it preventsthe longitudinal displacement of the socket-piece, and an adj ustingscrew working in said boss and aeting against said socket-piece to rockthe latter on said stud and adjnst the brush against the commutator.

3. In combination with a supporting stud, a commutator brush-holderconsisting ol' a socket-piece having a pivotal bearing on said stud, aboss having a screw for fixing it to said stud, a spring fixed at oneend to said boss and at the other to the socket-piece and tending topress the brush away from the commutator, and an adj usting screwworking in said boss and acting against said socketpiece to rock it onthe stud and press the brush against the commutator.

4. In combination with a supporting stud, a commutator brush-holderconssting of a metal sleeve fitting said stud, a boss engaging said studand mounted on said sleeve, a

socket-piece pivoted on said sleeve, and an adjusting screw engagingsaid boss and socketpiece for adj usting the socket-piece relatively tothe stud, whereby the holder may be removed bodily from the stud withoutimpairing its adjustment.

5. In combination with a supporting stud, a commutator brush-holderconsisting of a socket-piece having a pivotal connection with the stud,a boss fixed to the stud, and a metal sleeve interposed between the studand said socket-piece and boss, and serving to make an elfectiveelectrical connection between the brush-holder and stud.

6. In combination with a supporting stud, a commutator brush-holderconsisting of a IIO In witness whereof I have hereunto signed my name inthe presence of two subscribing Io Witnesses.

JAMES J. WOOD.

Witnesses:

ARTHUR O. FRASER, GEORGE H. FRASER.

